LED brightness

Why are the LEDs so bright?. I have Nanos and unos, (copies) but the on-board LEDs are far too bright. Anyone had any success in replacing the tiny 1k resistors- they are a bit too small for me to handle, although I could probably remove them easy enough. I guess once the project is completed they could be removed anyway.

With a bit of practice, SMD resistors can easily be replaced.

That's why you keep your Arduinos and modules after you blew them up.
Just like medicine students, use those that didn't make it to practice on.
Unlike those students, you don't need your target's approval for this in advance.

MAS3:
Unlike those students, you don't need your target's approval for this in advance.

Or a fridge to store the failures in :slight_smile:

Just put some black-marker on the too-bright LED?

...R

raymw:
Why are the LEDs so bright?. I have Nanos and unos, (copies) but the on-board LEDs are far too bright. Anyone had any success in replacing the tiny 1k resistors- they are a bit too small for me to handle, although I could probably remove them easy enough. I guess once the project is completed they could be removed anyway.

The LEDs on the Arduino boards are so bright because;
Most SMD LEDs are high performance type.
Most SMD LEDs do not have the domed bezel over the active light emitting area, this dome/lens spreads the light from the small emitting area. With no lens you are looking directly at the emitting area and so they appear so bright, also the sharpness of the LED gives them a more intense look than a LED with a lens.
Tom... :slight_smile:

Perhaps the earlier Leds were less efficient, and when the later batches arrived the manufacturer didn't know/care or not bother to change resistors. Perhaps more bright is more better. I think for the boards I'm putting in boxes, I'll remove Leds, but if it entails modifying too much (I won't need usb or connector) then it may be just as well to use the bare processor chip with only the few needed ancillary components.

I cover the LEDs with some 5-minute epoxy. When you mix it really well it introduces lots of microscopic bubbles into the epoxy, and then it dries semi-opaque.

raymw:
Why are the LEDs so bright?.

So you can blink them fast enough to appear dim.

GoForSmoke:
So you can blink them fast enough to appear dim.

Who are you calling dim? :slight_smile:

He wants indicators.

One simple Arduino demo is to blink led13 5ms ON, 20ms OFF (20% as bright as 100% ON) and then move the board back and forth quickly to show that led is blinking too fast to see as blinking when held near steady.

One purpose for a built-in led is to serve as a visibly blinking indicator light. If the led is not blinking, loop() is blocked, possibly locked out with something running (crash would reset) its own loop. The blink rate running slow means some process is hogging cycles.

remember that every 1ms of delay() wastes 16000 CPU cycles.

raymw:
Why are the LEDs so bright?. I have Nanos and unos, (copies) but the on-board LEDs are far too bright. Anyone had any success in replacing the tiny 1k resistors- they are a bit too small for me to handle, although I could probably remove them easy enough. I guess once the project is completed they could be removed anyway.

Because we have a bright future ahead !

I use a little household latex wall paint of any color. Put a dot of it on the LED with a toothpick. I tames the LED brightness.

If the led is too bright, use a bigger resistor or blink it with more OFF time.

They're not so bright when illuminating a white wall at even arm's length. That takes a lot of leds.

BJHenry:
I cover the LEDs with some 5-minute epoxy. When you mix it really well it introduces lots of microscopic bubbles into the epoxy, and then it dries semi-opaque.

Hot glue gun. Probably faster plus no risk if you spilled the glue in the wrong spot. Scrap it and it'll pop off. Epoxy don't come off easily once they harden